KB-24253: After an application that doesn’t allow windows switching has stopped, CTRL+ALT+DEL command stops working.

After window switching has been disabled and the application has stopped running, the CTRL+Alt+DEL command no longer works. How can I fix it?

Solution:

To do so, access Windows Start\Run menu, and type regedit. Then, access My Computer/HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Policies and, in Explorer folder, change NoLogoff key’s value from 1 to 0. In System folder, change all REG_DWORD keys from 1 to 0 too.